TOSS must not allow an unattended or automatic logon to the system.

STIG ID: TOSS-04-010430  |  SRG: SRG-OS-000480-GPOS-00229 |  Severity: high |  CCI: CCI-000366 |  Vulnerability Id: V-252945

Vulnerability Discussion

Failure to restrict system access to authenticated users negatively impacts operating system security.

Check

Verify TOSS does not allow an unattended or automatic logon to the system via a graphical user interface.

Note: This requirement assumes the use of the TOSS default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable.

Check for the value of the "AutomaticLoginEnable" in the "/etc/gdm/custom.conf" file with the following command:

$ sudo grep -i automaticloginenable /etc/gdm/custom.conf
AutomaticLoginEnable=false

If the value of "AutomaticLoginEnable" is missing or is not set to "false", this is a finding. If it does, this is a finding. Automatic logon as an authorized user allows access to any user with physical access to the operating system.

Fix

Configure TOSS to not allow an unattended or automatic logon to the system via a graphical user interface.

Add or edit the line for the "AutomaticLoginEnable" parameter in the [daemon] section of the "/etc/gdm/custom.conf" file to "false":

[daemon]
AutomaticLoginEnable=false